As electro-optical devices, for example, active drive type liquid crystal devices that are provided with a transistor for each pixel as an element that performs switching control of pixel electrodes, are known. Liquid crystal devices are used, for example, in direct view displays, light bulbs and the like.
In such liquid crystal devices, when light is incident, a liquid crystal material, an orientation film, and the like that configure a liquid crystal panel, and incidence light undergo a photochemical reaction, and ionic impurities are generated as reaction products. In addition, in a manufacturing process of a liquid crystal panel, the presence of ionic impurities that diffuse from a sealing material, a sealant or the like, to a liquid crystal layer, is also known. In particular, in a liquid crystal device that is used in an optical modulation means (a light bulb) of a projection type display device (a projector), since the luminous flux density of incidence light is higher than that in a direct view type display liquid crystal device, it is necessary to suppress a circumstance in which the ionic impurities exhibit an effect on the display.
For example, as means for suppressing an effect of the ionic impurities on the display, PTL 1 discloses a method that divides an effective pixel region into a plurality, and sweeps ionic impurities to a region on an outer side of an effective pixel region using a horizontal electric field that is applied by changing the amplitude for each region (or in other words, setting a different potential for each region).